Lighting unit



March 28, 1961 K. FRANCK LIGHTING UNIT Filed June 12, 1957 M a a T 7m P2 LIGHTING UNIT Filed June 12, 1957, Ser. No. 665,245

8 Claims. c1. 240-9 .This invention relates to a supporting member,having a cross-sectional shape substantially resemblingan inverted T,used to support light refracting plates.

It is an object of this invention to provide a transparent supportingmember that will support adjacent refracting plates and will refractlight passing through it.

It is a further object of this invention to provide the vertical lightincident surfaces of the supporting member with light refracting meansso that light fallingon the vertical light incident surfaces will beemitted from the vertical light emitting surfaces of the supportingmember in directions low enough to prevent glare.

It is yet another object of this invention to provide a horizontal crossmember integrally connected to the vertical member with light incidentsurfaces that are smooth and with light emitting surfaces having lightspreading means.

Other objects of my invention will hereinafter appear in thespecification taken in connection with the following drawings in whichthe same numerals, with prime marks added, indicate like parts.

Fig. 1 is a plan view showing the invention in use;

Fig. 2 is a perspective view of one embodiment of my invention;

Fig. 3 is a fragmentary bottom view of the invention illustrated in Fig.2;

Fig. 4 is a perspective view of a modification of the invention;

Fig. 5 is a fragmentary bottom view of the supporting member illustratedin Fig. 4;

Fig. 6 is a fragmentary sectional view taken along line 66 of Fig. 4 inthe direction of the arrow;

Fig. 7 is a perspective view of a further embodiment of the invention;and

Fig. 8 is a fragmentary bottom view of the structure illustrated in Fig.7.

In Fig. 1 the light source, illustrated as a series of fluorescent lamps10, is suitably mounted to ceiling 12. By means of brackets 14, rods 16,clamping members 18 and support members 20, a series of refractingplates 21, 22 and 23 are suspended from the ceiling to rest upon theflanges or base 24 of the support member 20. Since the detailedconstruction of plates 21, 22 and 23 do not form any part of thisinvention, no detail de-v scription of them will be herein included.

The supportmember 20 (Fig. 2) has a substantially horizontal base 24, asubstantially vertical body portion 26 integrally connected to the base,and a knob portion 28 at the upper extremityof body 26 integrallyconnected to the body and extending the full length of member 20.Referring to Fig. 2, it is seen that the cross-sectional shape of thissupporting member substantially resembles an inverted T wherein thehorizontal base 24 corresponds to the cross member of the T and thevertical body 26 corresponds to the vertical member of the T.

Body 26 (Fig. 2) is formed by a series or plurality of super-imposedprisms 40 extending laterally the full length of member 20. The upperextremity 42 of body 26, below the knob 28, is smooth, however, forapurpose to be hereinafter described.

Light entering one side of body 26from the light source 10 will berefracted downward by prisms 40 and emitted from the opposite side ofbody 26 in directions low enough to prevent glare. Thus, the light,depressed by prisms 40, is pre-controlled near the flanges or plates 21and 22 (i.e., where they rest on the T-bar surface 48) through which thelight might escape directly through the vertical portions of theflanges.

The flange member or base 24 of support member '20 has a smooth lightincident surface 48 upon which-the refracting plates 21, 22 and 23 willrest. In order that anyone taking a direct view from beneath one ofthese support members upwardly towards the light source will not receivethe direct glare of light source 10, the light emitting surface 50 ofbase 24 has a plurality of prisms 52 arranged parallel to the long axisof the support member. These prisms act to distribute light passingthrough base 24, so as to reduce the glare. i

The clamping member 18 is composed substantially of two U-shaped members60 and 61 (Fig. 1) adapted to be connected by means of a screw 64extending through members 60, 62.

The lower extremities 62 and 63, upon loosening of the screws 64, willfit over the knob 28 (Fig. 2) of the support member 20 and engage thesurface 42 of body 26. When tightened, the knob 28 will be held upon'the extremities 62, 63 of clamping member18. It being understood thatother means other than that-described hereinabove for securing the upperextremity of support member 20, could also be employed.

Another embodiment of my invention is illustrated in Figs. 4, 5 and 6.tions or flutes have been formed upon the body 26' of support member20'. larly to the prisms 40 hereinabove described in that they spreadthe light passing through the body 26. The light emitting surface 50'likewise has a plurality of prisms 52, however, in this modification,these prisms run substantially perpendicular to the body 26- so as togive a If desired, in addilongitudinal spreading of the light. tion toprisms 52 and in the ridges formed by prisms 52, a second row of prisms72 (Fig. 5) may be added,

rib projections rather than running vertically, up and down the side ofthe body 26" run substantially horizontally one above the other, thefull lateral length of the body 26" and scatter or spread the light overthe light incident surfaces of refracting plates 21, 22, 23.

Likewise, on the light emitting surface 50" of this modification is aplurality of prisms 52", similar to the prisms 52 of Fig. 2 hereinabovedescribed, to spread light emerg f ing from light emitting surface 50".

A material of manufacture giving excellent results has been found to beclear acrylic plastic, however, other clear plastic or transparentmaterials could be used with out departing from the spirit of thisinvention. The plastic support members themselves can be made from amold or, if desired, formed by an extrusion process.

I have hereinabove described what I consider to be the best embodimentsof my inventions. I do not wish, however, to be confined to theembodiments shown, but what I desire to cover by Letters Patent is setforth in the appended claims.

I claim:

1. In a lighting unit including a light source, a

In Fig. 4, a series of convex rib por- These rib portions 70 act simi- Iamass transmitting member below said light source, and a supportingclamp member extending downwardly adjacent an edge of said lighttransmitting member, the improvement comprising a transparent supportmember for said light transmitting member having a cross sectional shapesubstantially resembling an inverted T and including a substantiallyhorizontal base portion supporting an edge of said light transmittingmember, a substantially vertical body portion extending upwardly fromsaid base portion intermediate the width thereof, and a widened knobportion at the upper end of said body portion held by said clamp member,said vertical portion including prism means on the side adjacent saidlight source and said base portion including prism means on the bottomface thereof,.said prism means on said body portion and said baseportion being arranged to direct light incident thereon in directionslow enough to prevent glare.

2. A support member as in claim 1, wherein said prism means includes aplurality of parallel prisms on said base portion formed parallel to theplane of the vertical body portion and running the full length of saidbase portion.

3. A support member as in claim 1, wherein said prism means includes aplurality of parallel prisms on said base portion extendingperpendicularly to the plane of the vertical body portion.

4. A support member as in claim 3, wherein said prism means on the baseportion includes an additional single row of prisms positioned betweenthe ridges of two rows of said plurality of parallel prisms, said secondsingle row of prisms on the light emitting surface being parallel to theplane of said vertical body portion.

5. In combination with a light source, a light transmitting plate belowsaid light source, and a depending clamping member, a transparentsubstantially T-shaped supporting and retracting member, said memberincluding a substantially horizontal base portion supporting an edge ofsaid light transmitting member and a substantially vertical body portionjoined to said base portion intermediate the width thereof andsubstantially coextensive in length therewith, said vertical bodyportion including a widened knob portion at the top held by saidclamping member, said body portion and said base portion having glarereducing surfaces including prism means thereon to direct light incidenton said surfaces in directions to prevent glare in a location beneathsaid member.

6. In the combination according to claim 5 wherein said prism meansincludes a plurality of rows of prisms on the bottom face of said baseportion.

7. In the combination according to claim 5 wherein said prism meansincludes a plurality of substantially horizontal rows of prisms on saidbody portion.

8. In the combination according to claim 5 wherein said prism meansincludes prisms arranged to spread light in lateral directions.

References Cited in the file of this patent UNITED STATES PATENTS CullenJune 17, 1958

